Diecasting machine with force-balanced reciprocation apparatus and transferring means

ABSTRACT

A fast-acting diecasting machine including in combination, a die having at least one die platen which is reciprocatable between open and closed positions, a prime mover, reciprocation means disposed between said movable die platen and said prime mover for selectively and intermittently reciprocating said movable die platen between open and closed positions, transfer means for moving castings from said die cooperatively connected to said reciprocation means, means selectively and intermittently connecting said transfer means to said prime mover, means maintaining said reciprocation apparatus in a substantially force-balanced state during at least a major part of a platen reciprocation cycle, and means for injecting liquid matter into the die when it is closed. There is also disclosed a novel method for die casting.

United States Patent Inventor Franck M. Picker Oak Ridge, Tenn. Appl.No. 882,021 Filed Dec. 4, 1969 Patented Sept. 14, 1971 Assignee Pic-AirInc.

Oak Ridge, Tenn.

DIECASTING MACHINE WITH FORCE- BALANCED RECIPROCA'I'ION APPARATUS AND[56] References Cited UNITED STATES PATENTS 2,848,770 8/ 1958 Schuchardt164/344 UX Primary Examiner-Robert D. Baldwin Artorney- Paul E. HodgesABSTRACT: A fast-acting diecasting machine including in combination, adiehaving at least one die platen which is reciprocatable between openand closed positions, a prime mover, reciprocation means disposedbetween said movable die platen and said prime mover for selectively andintermittently reciprocating said movable die platen between open andclosed positions, transfer means for moving castings from said diecooperatively connected to said reciprocation means, means selectivelyand intermittently connecting said transfer means to said prime mover,means maintaining said reciprocation apparatus in a substantiallyforce-balanced state during at least a major part of a platenreciprocation cycle, and means for injecting liquid matter into the diewhen it is closed. There is also disclosed a novel method for diecasting.

l 5 CONTROL 68 TO INJECTION SYSTEM 51 BRAKE CLUTCH SYSTEM PATENTED SEP]4 |97| SHEET 1 BF 9 uxaim INVENTOR.

Franck M. Picker ATTORNEY.

PATENTEU SEPI 41911 3,604,499

sum 2 or 9 INVENTOR.

, Franck M. Picker ATTORNEY.

PATENIEU SEP14|97| 3 604L499 sum 5 [IF 9 PLATEN FORCE OMBINATION 6.C.+G.C.0UTPUT TORQUE I CRANK) AT CONSTANT INPUT PLATEN SPEED (COMBiNATIONG.C.+

2/1 CRANK) PLATEN SPEED AT CONSTANT CRANK INPUT=2 Edouwm SPEED AT\CONSTANT 0 INPUT some.

- --1aocnmx 1 PLATEN l RECIPROCATION CYCLE Fig.6

INVENTOR.

Franck M. Picker ATTORNEY.

PATENIEDSEPMIQ?! I 3504,4299 sum 7 or 9 INVENTOR. Franck M. Picker BY2., a. 7 46 ATTORNEY.

PATENIEBsEPMnm 3,604,499

sumaurs INVENTOR. Franck M. Picker ATTORNEY.

PATENTED sP14|91| 3.604.499

SHEET 9 OF 9 INVENTOR. Franck M. Picker QIEXQ ATTORNEY.

DIECASTING MACHINE WITH FORCE-BALANCED RECIPROCATION APPARATUS ANDTRANSFERRING MEANS This invention relates generally to die casting anddiecasting machines employing he method of injecting molten metal, underpressure, into a die cavity defined by a closed die.

Speaking generally, in die casting of metals or other materials, themolten metal is usually injected under pressure into a cavity defined bytwo or more closed die platens in accordance with the geometry of thedesired cast product. The injected molten metal is maintained within theclosed die until solidification occurs to at least the extent that themetal becomes self-sustaining. Thereupon, the die is opened and thesolidified product, termed a casting, is transferred out of any awayfrom the die.

Rapidly and repeatability are two major concerns in the field of diecasting. Manufacturing economics, enhanced by employing die casting,clearly, are further enhanced by fast diecasting operations. The priorart diecasting technology suffers the lack of fast diecasting techniquesand apparatus which will withstand repeated use over extended periods oftime. For example, prior to the present invention, a diecasting machinein the 30-ton class capable of performing 6 to 10 acceptable castingcycles per minute over extended periods was deemed extraordinary asrespects speed of casting. Fatigue and component wear resulting frommultitudinous die openings and closings under the relatively largedie-closing pressures routinely incurred accounted for a large portionof the prior art apparatus failures.

ln diecasting methods employing a die platen movable between open andclosed positions, apparatus is required to move the die platen rapidlyand repetitively along a reciprocation path. in such a method the dieplaten must reverse its direction at least twice during a casting cycle.Also, the die platen must remain stationary in the closed position for atime sufficient to permit solidification of the metal in the die cavity.Consequently, the apparatus which moves the die platen is subjectedduring a platen reciprocation cycle, to the force and stress attendingmovement of the die platen toward a closed position, followed by agreatly increased force and stress as a large die-closed holding forceis applied, followed by a relaxation of the die-closed holding force,and a reversed force and stress attending movement of the die platentoward an open position. in the prior art, this cyclic stressing of theapparatus resulted in frequent failure of the apparatus whichreciprocated the die platen, such failure occurring even more quickly asthe frequency of die platen reciprocation increased.

The large die-closing forces present in diecasting molten metal haveheretofore dictated the necessity of massive components in the dieplaten reciprocation apparatus and/or other portions of the diecastingmachine Massive machine components possess great inertia. Accordingly,powerful prime movers were required and great forces and stresses weredeveloped within the diecasting apparatus when these components wereplaced into motion, accelerated and stopped. in fast diecasting, theseforces and stresses reached enormous proportions which contributed toearly failure of the apparatus. Further, due to the great inertia of themassive components of the prior art diecasting machines, such machineswere not subject to fine control and were expensive to fabricate.Additionally, the prior art prime movers were necessarily of greatcapacity, hence very expensive.

Prior to the present invention, it was common practice to remove, orattempt to remove heat from the molten metal within the die cavity asrapidly as possible by subjecting the molten metal to a temperature asfar below the solidification temperature of the metal as practicable.For example, when casting a zinc alloy whose melting point is about 740F., it has been the practice heretofore to pass through the die acoolant maintained at a temperature of about 320 F. By this technique,there was developed a very large temperature gradient between thecoolant than did smaller temperature gradients.

It is noted that the relatively cold coolant of the prior art continuedto remove heat from the die, including the die cavity wall at all times,even when the die was open. The die cavity wall was thus very cool whenthe die was once again closed. When the molten metal was then injectedinto the closed and cooled die, the die cavity wall underwent animmediate and drastic increase in temperature. The net effect of theselarge temperature gradients on the die itself and more especially on thedie cavity wall was to subject the die metal to many cyclic temperaturechanges of great magnitude with concomitant metal fatigue and consequentfailure of the die metal. This deleterious effect upon the die metal wascompounded in the prior art by the relatively long time which elapsedbetween opening and closing of the die during a casting cycle. inaddition to the continued cooling effect on the die by the coolant, thelonger the die remained open during a casting cycle, the longer the timeduring which heat was being transferred from the die cavity surfaces tothe circulating coolant.

I Thus in the prior art, at all times when the die was open thereoccurred a continuing transfer of heat from the die cavity wall to thecoolant, i.e., a cooling of the die cavity wall. Of course, when the diewas again closed and molten metal injected into the die cavity, thereoccurred the above-described rapid and drastic increase in thetemperature of the die cavity wall. Repeated cooling and heating of thedie cavity wall produced metal fatigue and resultant cracks in the diecavity wall, thereby effectively destroying the die.

it is important to successful die casting that at the time molten metalis injected into the die that the die cavity wall be at a temperature asnear the melting temperature of the metal as possible for the reasonthat a cool die cavity wall will instantaneously remove excessiveamounts of heat from the molten metal in contact with the cool wall inpreference to removal of heat from the remainder 6 of the molten metal.This preferential cooling of the molten metal results in prematuresolidification of portions of the injected metal and resultant chillmarks on the metal casting. Moreover, where the casting has a thin wallthickness in part or in whole, premature solidification frequentlyprecludes complete filling of the die cavity in the area of the thinwall portion and produces a defective casting. In any event, the priorart taught that where thin wall thicknesses are involved, one should usevery fast injection and large pressures. Such conditions of castingcaused one to lose control over the injection operation and increasedthe frequency with which defective castings occurred.

l-lydraulically operated diecasting machines are common in the prior artand have been employed in attempts to provide the large forces requiredto operate prior art machines. These hydraulic systems, however, aresubject to many faults including their complexity and great cost ofmanufacture and maintenance.

It is therefore an object of this invention to provide a method andapparatus for fast, repetitive and controllable die casting especiallysuch a method and apparatus wherein the useful life of the diecastingapparatus and the die is extended beyond the useful life of theapparatus and die obtainable in the prior art. It is is another objectto provide a diecasting machine for rapid diecasting wherein the dieplaten reciprocation apparatus is maintained under substantiallybalanced forces during a major part of a platen reciprocation cycle. Itis a further object to provide a diecasting machine wherein molten metalmay be injected into the die cavity at relatively slower rates and underrelatively lower pressure while simultaneously substantially decreasingthe total casting cycle time over the time heretofore obtainable. It isa further object to provide a diecasting machine wherein the die is notsubjected to large temperature changes during a casting cycle. It is astill further object to provide a nonhydraulically operated diecastingmachine.

Other objects and advantages of the present invention will be evidentfrom the following description of the invention including the figures.

For present purposes, the discussion herein will be restricted todiecasting metal, but is not intended to so limit the invention. It willbe recognized by those skilled in the art of diecasting that the presentconcepts are useful in casting metals, alloys, plastics, and/or othermaterials, substances, etc.

FIG. 1 is a representation of one diecasting apparatus in accordancewith the present invention;

FIG. 2 is an exploded view of the means employed in the presentinvention to intermittently connect the several components of thecasting transfer mechanism to the prime mover;

FIG. 3 is a graphic representation of one casting cycle and depictingthe preferred cyclic positions of certain apparatus functions and theirrelative magnitudes, assuming a constant prime moving input throughoutthe cycle;

FIG. 4 is an expanded graphic representation of that portion of thecasting cycle of FIG. 3 which occurs between 67 and l57% and depictingthe torque output and several corresponding rotational positions of thecam of the-present invention;

FIG. 5 is an expanded graphic representation of that portion of thecasting cycle of FIG. 3 which occurs between 202% and about 292 /z anddepicting the torque output and several corresponding rotationalpositions of the cam of the present invention;

FIG. 6 is a graphic representation of a typical output speed and torqueof the Geneva Cross mechanism of this invention and of a typical linearspeed and torque of the die platen as moved by the combined actions ofthe Geneva Cross and crank mechanism (including the 2:1 gear ratiodiscussed hereinafter) of this invention;

FIG. 7 is a representation of one embodiment of a die employed in thepresent invention and depicting various features of such die;

FIG. 8 is an illustration of one embodiment of the cam and cam followerapparatus of this invention;

FIG. 9 and 9A are representations of several rotational andtranslational positions of the transfer and strip feed arms of thetransfer mechanism of this invention.

In accordance with the concepts of the present invention, the presentdiecasting machine comprises in combination a prime mover, a die havingat least one die platen which is reciprocatable between open and closedpositions, reciprocation means disposed between the movable die platenand the prime mover for selectively and intermittently reciprocating themovable die platen between its open and closed positions, meansoperatively associated with the reciprocation means and maintaining itin a substantially force-balanced state during the major part of aplaten reciprocation cycle, transfer means cooperatively connected withthe platen reciprocation means for moving castings from the die, andmeans for injecting liquid matter into the die when it is closed wherebythere is formed a cast product upon solidification of such liquidmatter. As desired, the casting apparatus may include means forperforming an operation upon the casting such as dressing, trimming, orthe like, such means being coordinated in function with the castingapparatus, particularly the casting transfer means.

It has been found possible in the present invention to obtain enhancedspeed and controllability of casting through coordinated functioning ofthe several elements of the casting machine as will appear more fullyhereinafter.

Referring now to FIG. 1, the diecasting machine of the present inventionis depicted schematically and comprises a prime mover 12 providing thedriving force for operation of a die reciprocation subassembly and atransfer subassembly which will be more fully described hereinafter.Also depicted in FIG. I is a molten metal injection subassemblyindicated generally at 37 and a trim-press subassembly indicatedgenerally at 47.

Referring further to FIG. 1 representative of a diecasting machinecomprising one embodiment of the present invention, power for drivingthe die platen reciprocation apparatus of the present invention isderived from a single motor l2 a conventional clutch and brake system 20interposed within its length. This drive shaft terminates in a sprocket14 around which is trained a chain 21, the chain also being trainedaround a second sprocket 22 keyed to a stub shaft 23 which in turncarries a worm 24. Accordingly, worm 24 is positively and mechanicallyconnected in driven relationship with motor 12 except as clutch 20 maybe disengaged.

Worm 24 serves as the driving gear for a Geneva Cross mechanismindicated generally at 11. Specifically, worm 24 engages the cam gear 25of the Geneva Cross mechanism such that rotation of worm 24 will rotategear 25. This gear 25 is provided with two convex cam sections 45, 46,two concave cam sections 26, 27 and two lugs 28, 29 for cooperativelyengaging the cross 30 of the mechanism. The periodic motion imparted tothe cross 30 is further transferred by the cross to a shaft 31 to whichthe cross is keyed. Shaft 31 carries a sprocket 32 keyed thereto so thateach movement of cross 30, effected by rotation of gear 25, results in acorresponding rotation of sprocket 32. This sprocket 32 is drivinglyconnected to a further sprocket 33 spaced apart from sprocket 32 andkeyed to a further shaft 6. Sprocket 32 is chosen in the depictedembodiment to be twice the diameter of sprocket 33 such that eachrotation of sprocket 32 results in two rotations of sprocket 33 hencetwo rotations of shaft 6. There is provided on shaft 6 a crank arm 7which is rotatable 360 with rotation of shaft 6. Crank arm 7 extendsperpendicularly from a shaft 6 and its outboard end receives, in pivotalconnection, one end of a link 8. The other end of link 8 is pivotallyconnected to a ram 9 to which is secured the movable die platen 10.Appropriate mounting means is provided for reciprocatably mounting thisram.

During each reciprocation cycle of the die platen, it may be visualizedthat worm 24 rotates gear 25 one revolution. For each such onerevolution there occurs two equal periodic rotational movements of cross30.

Each of these equal movements results in one quarter turn of cross 30,the cross being stationary during the intervals between the aforesaidtwo equal movements of the cross. The duration of the two nonactiveintervals are established by the arcuate lengths of the respectiveconvex cam sections 45 and 46. From FIG. 1 it can be seen that eachone-fourth turn of cross 30 results in a one-fourth turn of sprocket 32.By virtue of the size relationship between sprocket 32 and 33, eachonefourth rotation of sprocket 32 results in one-half rotation ofsprocket 33, hence one-half rotation of shaft 6 and movement of arm 7through an arc of 180. Each 180 movement of arm 7 moves ram 9 throughone-half of a platen reciprocation cycle. That is, for each one-fourthturn of cross 30 there occurs movement of die platen 10 from a positionof fully closed to fully opened or from fully opened to fully closed, asthe case may be.

It will be realized that when either of the cam lugs 28 and 29 of gear25 initially engages a slot 34 (typical) of the cross, the lug makesfirst contact nearest the peripheral end of the slot. Maximum torque andminimum speed were imparted to cross 30 at this point of contact.Further, at this rotational position of cross 30, it is assumed forpresent purposes that the die platen is in its full open position. Asthe cross is rotated, the cam lug moves radially inward and the torqueand speed imparted to the cross by the lug, decreases and increases,respectively, through each one-half platen reciprocation cycle. Therotational speed of the cross reaches a maximum and the torque impartedto shaft 31 by cross 30 reaches a minimum when the lug reaches its mostradially inward position. At the point when the lug escapes the slot,the torque and speed of cross 30 are again maximum and minimum,respectively. At this latter point, the die platen is in its fullyclosed position. The profile of the Geneva Cross outputs during both theopening and closing halves of such platen reciprocation cycle aredepicted graphically in FIGS. 3, 4, 5 and 6.

Simultaneously with the mechanical advantages developed by the GenevaCross mechanism, a similar mechanical advantage, having similar torqueand speed profiles, is developed by crank arm 7 and link 8 as arm 7 isrotated by shaft 6. The torque and speed components of this crankmechanism and the Geneva Cross mechanism combine additively and areimparted to ram 9. The resultant linear speed of the die platen laffixed to ram 9 is depicted graphically in FIGS. 3 and 6.

Referring specifically to FIG. 6, assuming a constant input (speed andtorque) to the Geneva Cross mechanism (G.C.), its output speed over 90(one-fourth of a casting cycle or onehalf of a die platen reciprocationcycle) is shown by the line labeled G.C. Output Speed at Constant Input.It is noted that upon actuation of the G.C. its output speed increasesslowly from dead stop (left of FIGURE), then accelerates rapidly to amaximum, followed by a rapid decrease in speed and a slow approach todead stop. Whereas this G.C. output itself has been found to provide adesirable output speed pattern for movement of a die platen, to use aG.C. alone for reciprocating the die platen is impracticable in that aninordinately massive G.C., superstructure, prime mover, etc. would berequired. Moreover, a G.C. alone would be subject to the hereinbeforedescribed large cyclically changing forces with concomitant wear, tear,failure, inability to control, slow action etc. of the diecastingapparatus.

Presently, it has been found that advantage can be taken of the G.C.output in diecasting by combining it with a crank mechanism indicatedgenerally at connected between the G.C. and a movable die platen suchthat the G.C. and crank outputs are combined to impart linear motion tothe die platen. The combined output speed from the G.C. and crank aredepicted in FIGS. 3 and 6. In the figures this output is shown as beingincreased by the 2:l gear ratio between sprockets 32, 33. It isrecognized that other gear ratios could be chosen and the 2:1 ratiodiscussed herein is not to be deemed limiting of the invention.

Review of FIGS. 3 and 6 shows that, in the present invention, at anytime during a casting cycle whereupon power from he prime mover isapplied to move the die platen, the apparatus is subjected to force andstress very slowly at first (left to right in the FIGURES), such forcethen accelerating rapidly to a maximum and then decelerating in asubstantially identical, but reverse, manner. In the absence of thepresent invention, the platen, in a typical one-half platenreciprocation cycle, e.g., open to close or close to open, wouldexperience an increase and decrease in speed as shown in FIG. 6, by theline labeled Platen Speed at Constant Input" (assuming a 2:1 gear ratioas discussed hereinbefore). It is noted that the present inventionprovides a significantly flatter curve at the beginning and end of theindicated period. This flatter curve portions are indicative of therelatively slow rate of approach of the platen to its open or closedposition as the case may be, and its similar slow rate of movement awayfrom either its open or closed position. Consequently, in the presentinvention the platen reciprocation apparatus is not subjected to thelarge shock or stress which attend the prior art machines due to theirabrupt change in direction when they move the platen through its open orclosed positions (i.e., where the direction of travel reverses). In thepresent invention the platen recipro cation apparatus moves the platenvery rapidly through a reciprocation cycle but it approaches and leavesan end point (open or closed) at almost zero speed to thereby avoid theopening and closing shock referred to above with resultantly reducedwear and tear of the machine. It is to be noted that this reduction inopening and closing shock is in addition to the force and stressreduction afforded by the cam-cam follower concept to be discussedhereinafter, these two concepts functioning simultaneously to enhancethe overall diecasting operation.

Also in accordance with the present invention, it has been discoveredthat the die platen reciprocation apparatus of the present diecastingmachine can be maintained under conditions of balanced force and stress,through the use of a combination including a cam 38 secured to a shaft 6disposed within and being an element of the die reciprocation apparatus,and a spring-loaded cam follower 39 riding against the cam surface suchthat rotation of the shaft and cam causes preselected transfer of energyfrom the die reciprocation apparatus to the spring of the cam followerand subsequent transfer of the energy from the spring back to thereciprocation apparatus. It is important for reasons which will appearhereinafter that the energy transfers be programmed and not allowed tooccur in an unordered manner.

It has been further found that selective compression of the springassociated with the cam follower provides a means for controlling themagnitude of energy accumulation and dispensation. Only that quantity ofenergy is accumulated which is excess in the system. This energy isdispensed only when such serves a useful purpose in the overall schemeof the apparatus functioning.

One suitable physical arrangement of the cam-cam follower mechanism isshown in FIGS. l and 2 wherein there is provided a shaft 6 with cam 38keyed to and rotatable therewith. As provided for in the presentinvention, shaft 6, by virtue of its position in the reciprocationapparatus, experiences as a torque force impressed thereupon, any stresspresent in the die reciprocation apparatus directed toward movement ofthe movable die platen 10 toward either an open or closed position.Consequently, it has been found possible to manipulate the torque forcesexperienced by shaft 6 in a manner so as, at substantially all timesduring a platen reciprocation cycle, to impose on such shaft acountertorque force by means of cam 38 and its spring loaded follower39, which is slidably mounted as by cylindrical housing 44. That is, inaccordance with the present concepts, spring 40 is cyclically compressedand expanded, hence the torque experienced by shaft 6 is controlled inaccordance with a planned program selected to develop torque valueswhich are opposite in direction but of approximately equal magnitude asthe torque values impressed upon the shaft by the platen reciprocationapparatus during a platen reciprocation cycle. Accordingly, at all timesduring a casting cycle, the present invention provides a proper force toshaft 6 which will balance the cumulative force ahead of the shaft(toward the die 13) against he cumulative force behind the shaft (towardthe prime mover 12), thereby achieving a balanced system.

It is important to note that the present invention provides for fullutilization of both the force provided by the prime mover and theseveral other forces and mechanical advantages associated with openingand closing the die platen. Such use of these forces is accomplishedwhile at the same time the heretofore expected wear and tear of themechanical apparatus and superstructure is substantially minimizedthrough the balancing of such forces in a programmed manner. Stillfurther, all the while the total system functions at a faster cyclingrate than the prior art. Speaking generally therefore, the presentinvention provides a diecasting method and apparatus wherein theapparatus functions faster, longer, and with less prime moving forcethan heretofore has been possible.

The advantages provided by the present invention are myriad. Aside fromthe aforementioned large decrease in wear and tear, this invention makesit possible to construct less massive casting apparatus componentsthereby decreasing the initial cost of fabricating a diecasting machine.Because the platen reciprocation apparatus is balanced, lessprime-moving power is required, for example it has been foundsatisfactory to utilize a 5 hp. motor as the prime mover undercircumstances which in the prior art required a 50 hp. motor.

Very importantly and contra to the prior art, the balanced platenreciprocation apparatus of the present invention renders the diecastingmachine amenable to fine control. This factor is of significance in thatfine control permits the elimination of lost time between steps of acasting cycle, thus minimizing the total cycle time and significantlyincreasing the productive output of a given machine. In addition,accurate control of the timing of cycle steps reduces defective castingsdue to irregular apparatus functioning, with resultant economic savings.

In one preferred embodiment of the present invention, shaft 6 isprovided with a cam having the configuration depicted in FIG. 8. Thetension on spring 40 retaining the cam follower 39 against thecircumference 41 of cam 38 is adjusted so as to provide an optimumconstant force base, specific for individual machines and desiredcasting cycles. From a knowledge of the casting cycle and the forcesdeveloped in the course of such cycle, an appropriate contour isdetermined and provided on cam 38.

Referring to FIGS. 3, 4 and 5, a typical casting cycle and therotational attitudes of the cam at several points during the cycle aredepicted. In any given casting cycle employing the present invention,the movable die platen 10 is moved to a closed position (the closedposition being defined as the point in the cycle where the two dieplatens contact without significant concomitant stress of the platen ortheir supporting superstructure), the platens and their supportingsuperstructure are then forced into a stressed state (termed thestressedclosed position for purposes this disclosure), the molten metalis injected into the die cavity and allowed to solidify, the closingstress on the die is relaxed, and the movable die platen is moved to anopen position to permit extraction of the casting, thereby completing acycle. As desired, of course other machine functions can be interposedwithin the cycle. The movable die platen preferably is moved rapidly andwithout stopping or interruption from its stressed-closed position,through its closed position, through its open position, through itsclosed position, and return to its stress-closed position. When the dieis in the latter position, the die reciprocation apparatus may bedeactivated for that period of time during which the die remainsstressed-closed.

From the foregoing discussion, it will be noted that the reciprocationapparatus for the movable die platen undergoes severe changes in loadduring a single casting cycle. Specifically, assuming a die-openstarting position, the reciprocation apparatus starts a cycle with azero load, i.e. no force or stress is imposed thereupon. The load of diereciprocation in a positive direction (acceleration) is them immediatelyplaced on the apparatus, such load increasing to a maximum at themidpoint between open and closed positions of the die and abruptlychanging to a negative load (deceleration) which load decreases to zeroat the closed position whereupon the reciprocation apparatus is requiredto supply a very sudden, large, positive, stress-closing force to thedie and retain such load during injection and solidification of thecasting metal. The reciprocation apparatus is also required to absorb(in a negative direction) this large stress-closing force when the dieis relaxed. During the die-opening half of a cycle, the reciprocationapparatus is subjected to loads which are the reverse of theaforedescribed closing loads. Clearly the wear and tear on thereciprocation apparatus can be severely great and good reason exists forthe massiveness and frequent breakdowns common in the prior art whichwas not afforded the benefits of the present invention.

It has been found, however, that the energy cam of the present inventionwill maintain the reciprocation apparatus for the movable die platen ina substantially force-balanced state during a casting cycle. This resultis accomplished by employing the cam and its spring-loaded cam followerto absorb energy during those parts of a casting cycle when excessenergy is present, such as during relaxation of the die from itsstress-closed position, and dispensing such accumulated energy duringthose parts of a casting cycle when extra" energy is needed, such asduring acceleration of the movable die platen.

In FIG. 8, cam 38 is shown as contoured for one typical casting cycle.The cam surface 41 in the depicted embodiment is of generally ellipticalgeometry but in other cycles it may assume other configurations. At oneapex of the ellipse, there is provided a notch 42 including within itsextent about 16 of the cam circumference. Accordingly, the cam follower39 abruptly enters the notch and equally abruptly exits the same as thecam rotates. Of course, while the follower resides in the notch, itneither imparts energy to nor absorbs energy from the cam. In Position 1of FIG. 4, the cam follower resides in notch 42 and the die platen is inits stressed-closed position. In the stress-closed position of the dieplaten, the die is not merely in contact with the other die section orsections as the case may be. Rather, the die is in a compressed stateand the framework of the die-casting machine is also stressed, i.e.there is a large quantity of energy stored in the die and its supportingstructural framework. I-Ieretofore, upon movement of the die platen fromits stress-closed position toward its open position, this stored energywas necessarily assumed by the die reciprocation apparatus. In thepresent invention, this stored energy is absorbed by the spring 40associated with the cam follower. This result is accomplished by thefollower moving out of the notch 42 and compressing the spring as thedie is relaxed from its stressed-closed position and is depicted by thenegative" (indicative of die opening) curve between 67 W of 157% in FIG.4.

As shown in FIG. 4 and the reference to FIGS. 3 and 6, the energyabsorbed in spring 40 is returned to the system as the die platen ismoved halfway (Position IV) toward its open position (Position VI). Thisreturn of energy enables the die reciprocation apparatus to overcome theinertia of the apparatus component and accelerate halfway between closedand open positions of the platen. It is noted that the energy dispensedby the spring increases immediately upon the die platen leaving itsclosed position, achieves a maximum, and then becomes less as the platenprogresses along its cycle, becoming minimum at the aforesaid halfwaypoint. The die platen speed (FIGS. 3 and 6) increases to a maximum atthis halfway point, whereupon the cam and its follower cause the springto commence absorbing energy with resultant deceleration of the dieplaten, rapidly at first but decreasing to minimum deceleration as theplaten achieves its fully open positions.

In FIG. 3, there is depicted a dwell time (IS'IW-ZOZW when the platen isin its fully open position. The duration of such dwell time beingaccomplished and established by the movement of the G.C. convex camsection 45 interacting with cross 30 of the G.C. Position VI of FIG. 3depicts the follower at the unnotched apex 43 of the elliptical camwhere it will be observed that continuous rotation of the cam wouldresult in immediate changeover of the spring from its open positiontoward its closed position and reduce the total casting cycle time.During the closing half of a casting cycle, the pattern of energycontrol by the spring is repeated as for the opening half of the cycle(see Positions VI-X and I, FIG. 5). In FIGS. 3-5, die platen closingforces are depicted as positive" to indicate that they are opposite tothe negative" opening forces.

In atypical casting cycle, the platen makes contact with the stationarydie platens about 8 prior to the stress-closed point in a platenreciprocation cycle. At this point, there is needed a large and suddenforce to stress-close the die. In the present invention, this force issupplied by spring 40 moving into a notch 42 and thereby in a brief spanof time imparting a large quantity of energy to the ram 9 of the platenreciprocation apparatus as is depicted in FIG. 5. For purposes ofclarity, the abscissa scales of FIGS. 4 and 5 are taken as representinga constant input rotation force so as to expand the scale in a linearmanner. If the mechanical advantages of the G.C. and crank wereinterjected into the FIGURES, the scale would not be linear across aplaten reciprocation cycle.

When a powerful prime mover is imparting large quantities of energy to amechanical system, any severance of the connection such as disengaging aclutch to separate the prime mover from its load, results in severestresses, i.e. shock, within the mechanical apparatus, especially if theapparatus must be braked. Because the die reciprocation apparatus of thepresent invention is in a balanced state, it may be disconnected at anypoint during the platen reciprocation cycle from the prime mover andbraked to a stop without introducing abrupt force imbalances which exertgreat strain and wear upon the apparatus. This capability provides thefurther benefit of fine control of the movement (or nonmovement) of thedie reciprocation apparatus. That is, because the apparatus ismaintained in a force-balanced state, it may be stopped or put in motionwith only a relatively small force which results in an excellent degreeof controllability. When the die is in its stressed-closed position theprime mover may be disconnected and, in effect, the die reciprocationapparatus hardly experiences the change.

With particular reference to FIGS. 1 and 2, the transfer subassembly ofthe present die-casting machine comprises a Geneva Cross mechanism 52receiving driving power from a wonn 50 interposed along the length ofdrive shaft 19 and meshing with gear 51 of the Geneva Cross mechanism.Laterally on opposite sides of gear 51 there are provided crosses 53 and54 keyed to respective shafts 55, 56 which are keyed to sprockets 57 and58 respectively. As is more particularly pointed out in FIG. 2, gear 51has provided on the opposite flat surfaces thereof respective camsections 59 and 60 and lugs 61 and 62. It will be realized that uponrotation of gear 51, lugs 61 and 62 respectively engage the slots 63 and64 (typical) of crosses 53 and 54 to effect periodic rotation of saidcrosses in accordance with the circumferential spacing of lugs 61 and 62on gear 51 and the rotational speed of gear 51.

Referring again to FIG. 1, sprocket 58 has trained therearound a chain65 which is further trained around sprocket 66 fixedly secured totubular shaft 67 whereupon rotation of cross 54 imparts rotation toshaft 67 as modified by the gear ratio between sprockets 58 and 66.Sprocket 57 has trained therearound a chain 68 which is further trainedaround sprocket 69 keyed to shaft 70 which is coincident along a majorportion ofits length with shaft 67 but independently rotatable thereof.

Preferably shaft 67 is hollow and shaft 70 extends therethrough toterminate in a crank 71 operatively inserted within a slot 72 of thecentral portion 73 of a strip feed arm 74 which is reciprocatablymounted by mounting means 75 and 76 secured on opposite ends of atransfer arm 93, provided on the terminal end of shaft 67. It may berealized, therefore, that rotation of the strip feed arm 74 is affectedthrough rotational movement of shaft 67 and translational reciprocationof the strip feed arm is affected through rotational movements of shaft70.

As indicated in FIG. I, strip feed arm 74 is provided at either of itsends with a core 77, 78 designed to be inserted within the die cavity 16during a casting operation. These cores are fixedly secured to the endsof the transfer arm.

Referring again to FIG. 1, it may be seen that shaft 67 is mechanicallyconnected by links 79 and 80 to ram 9 of the die reciprocationsubassembly. The respective ends 81, 82 (82 not visible) of links 79 and80 contact and ride against a circumferential shoulder 83 provided onshaft 67. These links 79 and 80 are rotatably retained by an appropriatemeans such as blocks 84, 85, 86, 87. The opposite ends 88 and 89 oflinks 79 and 80, respectively, are disposed in a contoured slot 90provided on ram 9 and movable therewith. It will be noted from observingthe contour of slot 90 that upon the movement of ram 9 from a closed dieposition toward an open die position, ends 88 and 89 of links 79 and 80will be carried with ram 9 during the initial interval of movement ofthe ram by virtue of end 88 being contacted by surface 98. Thereuponlink 75 is caused to rotate thereby causing end 81 of link 79 to bearagainst the annular shoulder 83 on shaft 67 and move shaft 67 along itslongitudinal axis a distance equal to the distance which ram 9 moveswhile end 88 of link 79 is in contact with surface 98 of slot 90. Aslink 75 is rotated, its end 88 slides into portion 91 of slot 90 and themovement of shaft 67 ceases while ram 9 continues its longitudinalmovement. Thus the movable die platen l and core 78 move simultaneouslyas the platen moves part way open. When ram 9 moves toward the closeddie position, end 89 of link 80 contacts end 92 of slot 90, causing thelink 80 to rotate and its end 82 (not visible in FIGURE to bear againstone side of the annular shoulder 83 on shaft 67 and move shaft 67 alongits longitudinal direction concurrently with ram 9 moving toward aclosed die position. Accordingly, ram 9 and shaft 67 move at the sametime and speed toward the die-closed position causing transfer arm 93,hence strip feed arm 74, also to move such that a core (78 or 77 as thecase may be) is in position to be inserted into the closed die throughan appropriate opening provided therein. Upon ram 9 moving die platen 10to its closed position, and with the strip feed arm in the appropriatelateral attitude with respect to the closed die, cross 53 is activatedand shaft 70 thereby rotated to cause crank 71 to become activated andeffect translational movement of strip feed arm 74 to the left in FIG. 1hence position core 78 within the die 13.

Upon completion of the die injection operation and after the casting hassolidified to the extent that it is self-supporting, ram 9 is movedtoward an open die position. By design, end 88 of link 79 contactssurface 98 of slot but its movement into portion 91 is delayed until ram9 has moved the die platen 10 to an open position sufficient forextraction of the casting by rotational movement of the transfer arm 93.

Precise coordination of the axial movements of ram 9 and shaft 67 ishighly desirable for the rapid machine movements contemplated in thepresent invention. With reference to FIG. 1, it may be seen that in thedepicted embodiment link 79 comprises two elongated sections indicatedat 79' and 70" which are joined by a helically coiled spring having oneof its end secured to section 79 and its other end secured to section79". Spring 100 is strongly torsion loaded at assembly thereby causingsections 79' and 79" to tend to rotate in opposite direction. Suchrotation is restrained by end 88 bearing against end 98 of slot 90(which tends to move ram 9 axially toward die 13) and by end 81 bearingagainst shoulder 83 (which tends to move shaft 67 axially also but inthe opposite direction from ram 9). The directional urging imparted toshaft 67 is transferred through shoulder 83 to end 82 (not visible),thence to link 80, and thence to end 89 which bears against end 92 ofslot 90 thereby creating a force loop whereby the ends 81, 88, 82, 89are at all times retained in intimate contact with their respectivelyadjacent bearing surfaces. When so maintained in position by the strongtorsion force of spring 100, these ends of the links cause the desiredprecise and definite axial movement of shaft 67 is response to axialmovement of ram 9. It is recognized that other linkage arrangementscould be made between ram 9 and shaft 67 which would bring about thedesired coordinated axial movements. For example, a single link havingits ends fitted in appropriate slots provided on ram 9 and shoulder 83could be employed but such requires more precise fitting between theends and their respective contact surfaces than does the depictedarrangement.

FIGS. 9 and 9A depicts, in steps, the several relative movements of thetransfer mechanism of this invention. Generally, shaft 67 is rotatableand axially slidable, its rotation being effected by intermittentconnection to motor 12 as brought about by lug 61 (FIGS. 1 and 2) orgear 51 engaging cross 54 which is mechanically joined to shaft 67 andits axial movement being effected by links 79, 80 as described above.Shaft 70 is likewise rotatable and axially slidable, its axial movementarising only as its connected strip feed arm 74 is moved axially (of theshaft) by axial movement of shaft 67 whose transfer arm 93 carries thestrip feed arm 74. Shaft 70, however, is rotatable in two separateincrements, once simultaneously and coextensively with shaft 67 byvirtue of lug 61 of gear 51 acting in common with crosses 53, 54 (FIGS.1 and 2) and once independently of shaft 67 by lug 62 of gear 51engaging cross 53 and rotate shaft 70. The purposes of these severalmovements will become apparent from FIGS. 9 and 9A. Specifically, inStep A, die 13 is shown to be fully open. With the die so positioned,strip feed arm 74 is positioned so as to feed a casting 97 (fromprevious cycle) within a trimming press 47. The casting is frozen ontocore 77. Core 78 on the opposite end of arm 74 is completely withdrawnfrom die 13. Also in Step A, shaft 67 is disposed at one of its limitsof longitudinal travel (in the up" direction of the FIGURE).

Step B of FIG. 9 shows the relative positions of the several componentsas die 13 is moved toward its closed position and shaft 67 is movedtherewith. In Step C, the die is fully closed and the casting is inposition for trimming. To this point, shaft 67 and arm 74 have onlymoved longitudinally but have reached their other longitudinal limit (inthe down direction in the FIGURE). In Step D, arm 74 is translatedlaterally to strip core 77 from casting 97 and feed core 78 into die 13.This translational movement is accomplished by lug 62 of gear 51engaging cross 53 and resultant rotation of shaft 70. As notedhereinbefore in connection with FIG. 1, shaft 70 is provided at one ofits ends with a crank 71 through whose action, rotation of shaft 70 isconverted into lateral translational movement of strip feed arm 74.

Upon completion of the strip feed action, molten metal is injected intothe die. As the metal solidifies, Step E, the trimming operation iscompleted, the trim press opens and in Step F the die platen 10 is movedtoward its open position, carrying with it the casting and shaft 67,hence arm 74 and core 87. In Step G, shaft 67 reaches its limit oflongitudinal travel and platen 10 continues its movement so as to becomeseparated from the casting. As desired, an appropriate ejector pin 99may be provided to assist extraction of the casting. As platen 10 movesaway from the casting, shafts 67 and 70 are simultaneously activated torotate equally, thereby simultaneously rotating transfer arm 93 andstrip feed arm 74 (Step H). By this means, there is no rotation of arm74 relative to arm 93, hence no lateral translational movement of arm 74as it is swung 180 to move casting 97 away from die 13 and into trimpress 47 to complete the cycle. In the absence of such simultaneousrotation of shafts 67 and 70, there would occur relative rotationtherebetween the movement of crank 71 such as would move arm 74laterally and result in casting 97 being out of position for trimmingwithout further complicated coordination of movements.

Additionally, the benefits of the present invention have been found bestachieved by continuously subjecting the die 13 (FIG. 7) to a coolantmaintained at a temperature of at least between about room temperatureand 50 percent of the solidification temperature of the casting metal.Preferably this coolant is circulated through a network of coolantchannels 94 (shown in section) within the die platens l0, l and veryclose to the die cavity wall 16. Still further enhancement of benefitshas been found possible by providing the strong die platens with aninsert 95 of less strength but having greater thermal conductivity thanthe platens. In this scheme of things, heat is rapidly withdrawn fromthe molten cast metal and the casting is caused to solidify very quicklyyet the die cavity wall never cools below about 50 percent of thesolidification temperature of the casting metal. It is of significancein the present invention that during the time that the die is open, heatis rapidly transferred to the die cavity wall to minimize cooling of thewall during the open interval.

Suitably, the channel system may be disposed about oneeighth inch fromthe die cavity wall 16. Water coolant maintained at a constanttemperature of about 70 F. to 360 F. may be continuously circulatedthrough the channel system when casting products having melting pointsas high as about 730 F. Other coolants, if desired, may be substitutedfor the water.

Conventional metal injection apparatus 37 (FIG. 1) comprising a pump 96for moving molten metal 35 from a heated vessel 36 to the die may beemployed in this invention.

Employing the present concepts, it has been possible, using a singlecavity die, to repetitively cast in excess of 60 acceptable products perminute each having a mass on the order of ounces. Because of thecapability of the present invention to maintain the die cavity wall ator near the desired casting temperature, products having about 0.030inch thin walls can be successfully cast at the aforesaid rate whilemaintaining a structurally sound casting having negligible chill marks.

Further, the hot die cavity wall and increased speed of platenreciprocation obtained with the present method permit the use of lowermolten metal injection pressures and slower injection rates, all with anoverall increase in the rapidity and repeatability of the castingoperation. For example, the present invention has been successfullyemployed to produce castings at the rate of 60 per minute, the castingshave wall portions of 0.100 inch thickness.

Whereas the present invention has been described by referringspecifically to the preferred crank and Geneva Cross mechanisms, othermechanical arrangements performing like functions could be substitutedwithout departing from the scope of this invention.

What Is Claimed Is: 1. Apparatus for die casting comprising amultisection die having at least one die section which is reciprocatablebetween open and closed positions and in cooperation with the remainderof the die defining a casting cavity when said movable die section is inits closed position, a prime mover, reciprocation apparatus interposedbetween said movable die section and said prime mover adapted tointermittently and cyclically move said die section between its open andclosed positions and including torque-manipulating means adapted tomaintain said reciprocation apparatus in a substantially force-balancedstate during a major portion of a reciprocation cycle of said diesection,

injection means adapted to admit liquid matter into said casting cavitywhen said die section is in its closed position where said liquid mattersolidifies into a self-supporting casting, core mount means includingcore members disposed thereon each movable by said core mount meansbetween a position at least partially within said casting cavity and aposition external of said casting cavity whereby said liquid mattersubstantially solidifies about that portion of said core positionedwithin said cavity and is subsequently moved away from said die withsaid core member,

transfer means connected with said core mount means so as to move saidcore mount means and said core members between the several positions ofsaid core members, and

means connecting said transfer means to said reciprocation apparatus soas to move said transfer means and said core members in coordinationwith reciprocation of said die section whereby one of said core membersis positioned in register with said casting cavity when said die sectionis in its closed position.

2. The invention of claim 1 wherein said reciprocation apparatuscomprises shaft means first mechanical means connecting said shaft meansto said prime mover for rotation of said shaft,

second mechanical means connecting said shaft means to saidreciprocatable die section,

energy transfer means disposed in energy transfer relationship with saidshaft and operative in response to the torque forces imposed on saidshaft to exchange torque forces between itself and said shaft so as toreduce the torque force imposed on said shaft.

3. The invention of claim 2 wherein said energy transfer means comprisesa cam secured to said shaft and rotatable therewith and a cam followerbiased in contact with said cam whereby rotation of said cam results incyclic change in the degree of bias force exerted against said cam bysaid cam follower and resultant cyclic change in the torque experiencedby said shaft.

4. The invention of claim 1 wherein said transfer means includes a firstelement adapted to impart rotational movement to said core mount meansto swing said core members between their several positions and a secondelement adapted to effect lateral movement of said core mount means andcore members so as to simultaneously move one of said core members toits position within said casting cavity and to extract the other of saidcore members from a casting which has previously been swung to astripping position outside said casting cavity.

5. The invention of claim 1 and including a stripping station spacedfrom said die and including means for grasping a casting attached to acore member swung to said station whereby said casting is retained atsaid station when said core member is moved away from said station.

6. In a die-casting machine having a multisection die, at least one diesection of which is reciprocatable between open and closed positions bya reciprocation apparatus and cooperating with the remainder of the dieto define a casting cavity when in its closed stripping position,apparatus for transferring a casting from said die cavity to a positionoutside said die cavity and comprising core support means rotatablymounted adjacent said die,

first and second core members disposed on said core support means firstrotatable and axially movable shaft means carrying said core mount meanson one of its ends and connected at its opposite end to a source ofpower for rotation whereby upon rotation of said shaft means said coresupport means and said core members are swung about the axis of saidshaft means so as to move that core having a casting thereon away fromsaid die cavity and to swing the other of said core members intoregister with said die cavity,

second rotatable shaft means connected at one of its ends to said sourceof power for rotation of said second shaft means and connected at itsother end to said core support means whereby rotation of said secondshaft moves said core support means in a direction substantiallyperpendicular to the axis of said second shaft means so as to move thatcore member registered with said die cavity into said die cavity andsimultaneously extract the other of said core members from the castingsolidified thereon, means cyclically and intermittently connecting saidfirst and second shaft means, respectively, to said source of power,means connecting said first shaft means to said die sectionreciprocation apparatus so as to move said first shaft means, said coresupport means and said core members in coordination with thereciprocatory movement of said die section and in a direction parallelto the reciprocatory path of said die section and thereby effectingremoval of a solidified casting from that portion of the die which isstationary. 7. The invention of claim 6 wherein said core members areoppositely disposed on said core mount means.

8. The invention of claim 6 wherein said first and second shaft meansare coaxial.

9. The invention of claim 6 wherein said second shaft is connected tosaid core mount means by a crank member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 604,499 Dated September 14, 1971 Inventor(s) Franck M. Picker It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line ,2, change "he" to --the--.

Column 1, line 53, following "machine" and before "Massive",

insert a period.

Column 1, line 72, change "320" to --32--.

Column 2, line 36, following "remainder", delete --6--.

Column 10, line 27, change "70" to --79"--.

Signed and sealed this 1 th day of April 1 972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK At testing Officer Commissionerof Patents QM (1069) uscoMM-oc sosnw e a U 5 GOVERNMENT PHINT'NG OFFICE:IQD 0-356-33l

1. Apparatus for die casting comprising a multisection die having atleast one die section which is reciprocatable between open and closedpositions and in cooperation with the remainder of the die defining acasting cavity when said movable die section is in its closed position,a prime mover, reciprocation apparatus interposed between said movabledie section and said prime mover adapted to intermittently andcyclically move said die section between its open and closed positionsand including torque-manipulating means adapted to maintain saidreciprocation apparatus in a substantially forcebalanced state during amajor portion of a reciprocation cycle of said die section, injectionmeans adapted to admit liquid matter into said casting cavity when saiddie section is in its closed position where said liquid mattersolidifies into a self-supporting casting, core mount means includingcore members disposed thereon each movable by said core mount meansbetween a position at least partially within said casting cavity and aposition external of said casting cavity whereby said liquid mattersubstantially solidifies about that portion of said core positionedwithin said cavity and is subsequently moved away from said die withsaid core member, transfer means connected with said core mount means soas to move said core mount means and said core members between theseveral positions of said core members, and means connecting saidtransfer means to said reciprocation apparatus so as to move saidtransfer means and said core members in coordination with reciprocationof said die section whereby one of said core members is positioned inregister with said casting cavity when said die section is in its closedposition.
 2. The invention of claim 1 wherein said reciprocationapparatus comprises shaft means first mechanical means connecting saidshaft means to said prime mover for rotation of said shaft, secondmechanical means connecting said shaft means to said reciprocatable diesection, energy transfer means disposed in energy transfer relationshipwith said shaft and operative in response to the torque forces imposedon said shaft to exchange torque forces between itself and said shaft soas to reduce the torque force imposed on said shaft.
 3. The invention ofclaim 2 wherein said energy transfer means comprises a cam secured tosaid shaft and rotatable therewith and a cam follower biased in contactwith said cam whereby rotation of said cam results in cyclic change inthe degree of bias force exerted against said cam by said cam followerand resultant cyclic change in the torque experienced by said shaft. 4.The invention of claim 1 wherein said transfer means includes a firstelement adapted to impart rotational movement to said core mount meansto swing said core members between their several positions and a secondelement adapted to effect lateral movement of said core mount means andcore members so as to simultaneously move one of said core members toits position within said casting cavity and to extract the other of saidcore members from a casting which has previously been swung to astripping position outside said casting cavity.
 5. The invention ofclaim 1 and including a stripping station spaced from said die andincluding means for grasping a casting attached to a core member swungto said station whereby said casting is retained at said station whensaid core member is moved away from said station.
 6. In a die-castingmachine having a multisection die, at least one die section of which isreciprocatable between open and closed positions by a reciprocationapparatus and cooperating with the remainder of the die to define acasting cavity when in its closed stripping position, apparatus fortransferring a casting from said die cavity to a position outside saiddie cavity and comprising core support means rotatably mounted adjacentsaid die, first and second core members disposed on said core supportmeans first rotatable and axially movable shaft means carrying said coremount means on one of its ends and connected at its opposite end to asource of power for rotation whereby upon rotation of said shaft meanssaid core support means and said core members are swung about the axisof said shaft means so as to move that core having a casting thereonaway from said die cavity and to swing the other of said core membersinto register with said die cavity, second rotatable shaft meansconnected at one of its ends to said source of power for rotation ofsaid second shaft means and connected at its other end to said coresupport means whereby rotation of said second shaft moves said coresupport means in a direction substantially perpendicular to the axis ofsaid second shaft means so as to move that core member registered withsaid die cavity into said die cavity and simultaneously extract theother of said core members from the casting solidified thereon, meanscyclically and intermittently connecting said first and second shaftmeans, respectively, to said source of power, means connecting saidfirst shaft means to said die section reciprocation apparatus so as tomove said first shaft means, said core support means and said coremembers in coordination with the reciprocatory movement of said diesection and in a direction parallel to the reciprocatory path of saiddie section and thereby effecting removal of a solidified casting fromthat portion of the die which is stationary.
 7. The invention of claim 6wherein said core members are oppositely disposed on said core mountmeans.
 8. The invention of claim 6 wherein said first and second shaftmeans are coaxial.
 9. The invention of claim 6 wherein said second shaftis connected to said core mount means by a crank member.